Buggy code:
public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport implements ConfigurableBeanFactory { private BeanFactory parentBeanFactory ; private ClassLoader beanClassLoader = ClassUtils . getDefaultClassLoader ( ) ; private ClassLoader tempClassLoader ; private boolean cacheBeanMetadata = true ; private BeanExpressionResolver beanExpressionResolver ; private ConversionService conversionService ; private final Set < PropertyEditorRegistrar > propertyEditorRegistrars = new LinkedHashSet < PropertyEditorRegistrar > ( 4 ) ; private TypeConverter typeConverter ; private final Map < Class < ? > , Class < ? extends PropertyEditor > > customEditors = new HashMap < Class < ? > , Class < ? extends PropertyEditor > > ( 4 ) ; private final List < StringValueResolver > embeddedValueResolvers = new LinkedList < StringValueResolver > ( ) ; private final List < BeanPostProcessor > beanPostProcessors = new ArrayList < BeanPostProcessor > ( ) ; private boolean hasInstantiationAwareBeanPostProcessors ; private boolean hasDestructionAwareBeanPostProcessors ; private final Map < String , Scope > scopes = new HashMap < String , Scope > ( 8 ) ; private SecurityContextProvider securityContextProvider ; private final Map < String , RootBeanDefinition > mergedBeanDefinitions = new ConcurrentHashMap < String , RootBeanDefinition > ( 64 ) ; private final Map < String , Boolean > alreadyCreated = new ConcurrentHashMap < String , Boolean > ( 64 ) ; private final ThreadLocal < Object > prototypesCurrentlyInCreation = new org . springframework . core . NamedThreadLocal < Object > ( "Prototype<seq2seq4repair_space>beans<seq2seq4repair_space>currently<seq2seq4repair_space>in<seq2seq4repair_space>creation" ) ; public AbstractBeanFactory ( ) { } public AbstractBeanFactory ( BeanFactory parentBeanFactory ) { } public Object getBean ( String name ) throws BeansException { } public < T > T getBean ( String name , Class < T > requiredType ) throws BeansException { } public Object getBean ( String name , Object ... args ) throws BeansException { } public < T > T getBean ( String name , Class < T > requiredType , Object ... args ) throws BeansException { } @ SuppressWarnings ( "unchecked" ) protected < T > T doGetBean ( final String name , final Class < T > requiredType , final Object [ ] args , boolean typeCheckOnly ) throws BeansException { } public boolean containsBean ( String name ) { } public boolean isSingleton ( String name ) throws NoSuchBeanDefinitionException { } public boolean isPrototype ( String name ) throws NoSuchBeanDefinitionException { } public boolean isTypeMatch ( String name , Class < ? > targetType ) throws NoSuchBeanDefinitionException { } public Class < ? > getType ( String name ) throws NoSuchBeanDefinitionException { } @ Override public String [ ] getAliases ( String name ) { } public BeanFactory getParentBeanFactory ( ) { } public boolean containsLocalBean ( String name ) { } public void setParentBeanFactory ( BeanFactory parentBeanFactory ) { } public void setBeanClassLoader ( ClassLoader beanClassLoader ) { } public ClassLoader getBeanClassLoader ( ) { } public void setTempClassLoader ( ClassLoader tempClassLoader ) { } public ClassLoader getTempClassLoader ( ) { } public void setCacheBeanMetadata ( boolean cacheBeanMetadata ) { } public boolean isCacheBeanMetadata ( ) { } public void setBeanExpressionResolver ( BeanExpressionResolver resolver ) { } public BeanExpressionResolver getBeanExpressionResolver ( ) { } public void setConversionService ( ConversionService conversionService ) { } public ConversionService getConversionService ( ) { } public void addPropertyEditorRegistrar ( PropertyEditorRegistrar registrar ) { } public Set < PropertyEditorRegistrar > getPropertyEditorRegistrars ( ) { } public void registerCustomEditor ( Class < ? > requiredType , Class < ? extends PropertyEditor > propertyEditorClass ) { } public void copyRegisteredEditorsTo ( PropertyEditorRegistry registry ) { } public Map < Class < ? > , Class < ? extends PropertyEditor > > getCustomEditors ( ) { } public void setTypeConverter ( TypeConverter typeConverter ) { } protected TypeConverter getCustomTypeConverter ( ) { } public TypeConverter getTypeConverter ( ) { } public void addEmbeddedValueResolver ( StringValueResolver valueResolver ) { } public String resolveEmbeddedValue ( String value ) { String result = value ; for ( StringValueResolver resolver : this . embeddedValueResolvers ) { <START_BUG> result = resolver . resolveStringValue ( result ) ; <END_BUG> } return result ; } public void addBeanPostProcessor ( BeanPostProcessor beanPostProcessor ) { } public int getBeanPostProcessorCount ( ) { } public List < BeanPostProcessor > getBeanPostProcessors ( ) { } protected boolean hasInstantiationAwareBeanPostProcessors ( ) { } protected boolean hasDestructionAwareBeanPostProcessors ( ) { } public void registerScope ( String scopeName , Scope scope ) { } public String [ ] getRegisteredScopeNames ( ) { } public Scope getRegisteredScope ( String scopeName ) { } public void setSecurityContextProvider ( SecurityContextProvider securityProvider ) { } @ Override public AccessControlContext getAccessControlContext ( ) { } public void copyConfigurationFrom ( ConfigurableBeanFactory otherFactory ) { } public BeanDefinition getMergedBeanDefinition ( String name ) throws BeansException { } public boolean isFactoryBean ( String name ) throws NoSuchBeanDefinitionException { } @ Override public boolean isActuallyInCreation ( String beanName ) { } protected boolean isPrototypeCurrentlyInCreation ( String beanName ) { } @ SuppressWarnings ( "unchecked" ) protected void beforePrototypeCreation ( String beanName ) { } @ SuppressWarnings ( "unchecked" ) protected void afterPrototypeCreation ( String beanName ) { } public void destroyBean ( String beanName , Object beanInstance ) { } protected void destroyBean ( String beanName , Object beanInstance , RootBeanDefinition mbd ) { } public void destroyScopedBean ( String beanName ) { } protected String transformedBeanName ( String name ) { } protected String originalBeanName ( String name ) { } protected void initBeanWrapper ( BeanWrapper bw ) { } protected void registerCustomEditors ( PropertyEditorRegistry registry ) { } protected RootBeanDefinition getMergedLocalBeanDefinition ( String beanName ) throws BeansException { } protected RootBeanDefinition getMergedBeanDefinition ( String beanName , BeanDefinition bd ) throws BeanDefinitionStoreException { } protected RootBeanDefinition getMergedBeanDefinition ( String beanName , BeanDefinition bd , BeanDefinition containingBd ) throws BeanDefinitionStoreException { } protected void checkMergedBeanDefinition ( RootBeanDefinition mbd , String beanName , Object [ ] args ) throws BeanDefinitionStoreException { } protected void clearMergedBeanDefinition ( String beanName ) { }

Fix:
result = ( result == null ) ? null : resolver . resolveStringValue ( result ) ;